1. Field of the Invention
The invention relates to a coaxial cigarette comprising a coaxial rod, the core of the rod consisting of a different mixture of a material smouldering substantially without residue, in particular tobacco material, than the periphery of the rod, a sheath of the rod core of cigarette paper or tobacco sheet, a sheath of the rod periphery of cigarette paper or tobacco sheet, and a filter mouthpiece.
2. Description of the Prior Art
In various publications socalled "coaxial smokable articles" have been described. As a rule, these coaxial smokable articles are coaxial cigars or cigarettes having an inner core which is surrounded by a jacket of tobacco material. Such a coaxial cigarette was mentioned for example in FR-PS 998,556. The inner core thereof consisted of a tobacco of relatively low quality and the jacket thereof of a higher quality tobacco. This made it possible to achieve savings with regard to the tobacco material required.
Further prior publications also disclose such coaxial cigarettes, for example FR-PS 1,322,254, U.S. Pat. Nos. 3,614,956, 4,219,031, GB-OS 2,070,409 and GB-PS 1,086,443. A relatively highly developed coaxial cigarette is described in DE-OS 3,602,846. This however does not have any filter which could trap the undesirable smoke constituents.
In the coaxial cigarette according to U.S. Pat. No. 3,356,094 an inner hollow tube and an aerosol chamber having a narrow outlet are provided. However, this type of coaxial cigarette is practically not usable because it can be made only by employing a very expensive method and in addition due to the various constituents separate from each other it has an unusual smoke pattern which is characteristic of said constituents.
From DE 40 20 496 A1 a coaxial cigarette is known which is surrounded by a metallic foil sheath. The space containing the tobacco thereby formed is surrounded by a hollow cylinder of carbon combustible material which is surrounded by an air-permeable sheath. Finally, the known cigarette has a filter at one end.
If the known cigarette according to DE 40 20 496 A1 had a draw resistance of 10 mm WC/cm tobacco rod, by conversion therefrom 0.10 to 0.33 mm WC cm.sup.2 /mg would result for the core.
This configuration leads both to an increase in costs and to a complication of the manufacture of this known coaxial cigarette and at the same time the acceptance of this product by the consumer decreases because both an unusual smoke pattern and a reduced smoking experience when smoking this coaxial cigarette result.
The coaxial cigarette of this type according to DE-PS 3,743,597 is additionally provided with a ventilated coaxial filter having a filter core, the inner diameter of which corresponds substantially to the diameter of the inner core of the coaxial cigarette and which has a filter jacket. In addition, the filter core has an air-impermeable sheath. The filter jacket has an air-permeable sheath. The sheath of the inner core of the coaxial cigarette and the sheath of the outer jacket thereof are provided with glow salts, the draw resistance of the inner core being lower than the draw resistance of the outer jacket of the coaxial cigarette. This known coaxial cigarette has the advantage that undesirable combustion products are retained to a large extent in the coaxial filter.
A disadvantage of the coaxial cigarette of this type is however that the production thereof is relatively complicated and expensive.